Merge pull request #9 from pgier/multi-stage-docker-build

update Dockerfile to use multi-stage build

Dockerfile

@@ -1,21 +1,17 @@
-FROM openshift/origin-base
+FROM registry.svc.ci.openshift.org/openshift/release:golang-1.10 AS builder
+WORKDIR /go/src/github.com/jimmidyson/configmap-reload
+COPY . .
+RUN make out/configmap-reload
 
-ENV GOPATH /go
-RUN mkdir -p $GOPATH/bin
-
-COPY . $GOPATH/src/github.com/jimmidyson/configmap-reload
-
-RUN yum install -y golang make git && \
-   cd $GOPATH/src/github.com/jimmidyson/configmap-reload && \
-   PATH=$PATH:$GOPATH/bin make out/configmap-reload GOPATH=$GOPATH && cp $GOPATH/src/github.com/jimmidyson/configmap-reload/out/configmap-reload /usr/bin/configmap-reload && \
-   yum autoremove -y golang make git && yum clean all
-
-LABEL io.k8s.display-name="configmap reload" \
+FROM  registry.svc.ci.openshift.org/openshift/origin-v4.0:base
+LABEL io.k8s.display-name="OpenShift ConfigMap Reload" \
       io.k8s.description="This is a component reloads another process if a configured configmap volume is remounted." \
       io.openshift.tags="kubernetes" \
       maintainer="Frederic Branczyk <[email protected]>"
 
-# doesn't require a root user.
-USER 1001
+ARG FROM_DIRECTORY=/go/src/github.com/jimmidyson/configmap-reload
+COPY --from=builder ${FROM_DIRECTORY}/out/configmap-reload  /usr/bin/configmap-reload
+
+USER nobody
 
 ENTRYPOINT ["/usr/bin/configmap-reload"]